US3390441A - Apparatus and method for reducing the number of unnecessary cuts of yarn - Google Patents

Apparatus and method for reducing the number of unnecessary cuts of yarn Download PDF

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Publication number
US3390441A
US3390441A US599481A US59948166A US3390441A US 3390441 A US3390441 A US 3390441A US 599481 A US599481 A US 599481A US 59948166 A US59948166 A US 59948166A US 3390441 A US3390441 A US 3390441A
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United States
Prior art keywords
yarn
signal
sensitivity
discriminator
double
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Expired - Lifetime
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US599481A
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English (en)
Inventor
Felix Ernst
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Zellweger Uster AG
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Zellweger Uster AG
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
    • H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
    • H03K3/26—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback
    • H03K3/28—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback using means other than a transformer for feedback
    • H03K3/281—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback using means other than a transformer for feedback using at least two transistors so coupled that the input of one is derived from the output of another, e.g. multivibrator
    • H03K3/286—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback using means other than a transformer for feedback using at least two transistors so coupled that the input of one is derived from the output of another, e.g. multivibrator bistable
    • H03K3/2893—Bistables with hysteresis, e.g. Schmitt trigger
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H63/00—Warning or safety devices, e.g. automatic fault detectors, stop-motions ; Quality control of the package
    • B65H63/06—Warning or safety devices, e.g. automatic fault detectors, stop-motions ; Quality control of the package responsive to presence of irregularities in running material, e.g. for severing the material at irregularities ; Control of the correct working of the yarn cleaner
    • B65H63/062—Electronic slub detector
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H2701/00—Handled material; Storage means
    • B65H2701/30—Handled filamentary material
    • B65H2701/31—Textiles threads or artificial strands of filaments

Definitions

  • ABSTRACT OF THE DISCLOSURE An apparatus and method for controlling the sensitivity of a yarn cleaner in dependence on the detection of a slub or double thread.
  • a store records whether a cut is made due to a slub or double thread and subsequently controls the sensitivity of the yarn cleaner in dependence thereon at least during reinsertion of the cut yarn cleaner.
  • this short length of yarn will presumably have a cross-section of approximately 100%, or 200% in the case of a double thread. Due to the irregularity of the yarn, however, greater differences can occur in isolated cases. For example, a thin part of a double thread with 140% of the normal cross-section can he accidentally inserted into the cleaner. On the other hand, a single thread could even be inserted which, at the point of entry, has a thick section of 140% (+40%).
  • a diagram of the cross-section pattern will show that thick sections such as these are by no means rare.
  • the cleaner should not be adjusted in such a way to only respond with certainty to the insertion of a yarn with a 200% cross-section but rather should also respond to a cross-section of 140%.
  • the single thread is also cut in the aforementioned case due to the accidental slub of 140% thickness. For this reason, it is impossible to prevent a certain percentage of single threads being cut for an almost one hundred percent detection of these double threads. In the case of a uniform yarn, the percentage is somewhat smaller but is a little larger in the case of an irregular or non-uniform yarn. Although the percentage can be reduced in the case of irregular yarns, by increasing the response limit of the cleaner, the percentage of double threads which are not detected on introduction is thereby increased.
  • the invention relates to an apparatus and method for reducing the number of needless cuts of yarn by yarn cleaners having a discriminator for detecting slubs, a discriminator for detecting double threads and a cutting unit which reacts to a signal from either discriminator.
  • the apparatus of the invention includes a circuit arrangement having a store or storage circuit on which at least one of the discriminators acts and a control member which responds to the condition of the storage circuit.
  • the storage circuit reacts to an output signal from either of the discriminators when a yarn is cut to store the signal and to adjust the sensitivity of the double thread discriminator with respect to the stored signal.
  • the storage circuit includes a means for erasing the stored signal after the occurrence of a subsequent predetermined signal from the slub discriminator or upon the re-insertion of a yarn in the cleaner.
  • the method of the invention includes the steps of passing a yarn through a yarn cleaner to detect the pressence of a slub or double thread by emitting signals corresponding to the presence of either.
  • the signals are directed to a common store for adjusting the sensitivity of the yarn cleaner in dependence on the signal received whereby when a double thread is detected the sensitivity of the yarn cleaner is adjusted to a high value and when a slub is detected the sensitivity is adjusted to a low value.
  • the method also includes the step of erasing the stored signal emitted in response to the presence of a double thread in order to reduce the sensitivity of the yarn cleaner. This step is actuated upon the occurrence of a signal of predetermined value in response to the subsequent detection of a slub or upon re-insertion of the yarn in the cleaner.
  • FIG. 1 graphically illustrates the frequency of occurrence of slub and double thread thicknesses in a yarn
  • FIG. 2 illustrates a block diagram of a conventional yarn cleaner
  • FIG. 3 illustrates a block diagram of a yarn cleaner incorporating a store according to the invention
  • FIG. 4 schematically illustrates a circuit arrangement for a slub discriminator
  • FIG. 5 schematically illustrates a circuit arrangement for a double thread discriminator
  • FIG. 6 schematically illustrates a circuit arrangement for a store of the invention.
  • FIG. 7 schematically illustrates a common circuit arrangement for slub and double thread discriminators and a store.
  • the frequency of occurrence of the distribution of cross-sectional frequencies of a single yarn 10 and a double yarn 20 are plotted with the cross sectional values Q as the abscissa in percentage of the average cross-section and the relative frequencies f for each of the cross-sectional values Q are plotted as the ordinates.
  • the response limit of a yarn clearner is set at 200% for double threads, then only 50% of the double threads passing through the yarn cleaner are detected while all the double threads of an overall cross-section less than 200% (in this case, 50% of all double threads corresponding to the overall frequency at 200%) are ignored. On the other hand, only those slubs which take up 200% of the normal cross-section are separated out although their frequency is extremely low. If, by contrast, the response limit of the yarn cleaner is set at 100%, every single yarn with a cross-section of 100% and more is cut, i.e. 50% of all cases.
  • a yarn cleaner for the detection both of slubs and a double threads of a yarn 1 has a measuring head 2 for passage of the yarn 1 in which associated amplifiers (not shown) may also be accommodated.
  • the yarn cleaner includes a discriminator 3 for slubs which emits a signal to a cutting unit 5 when a slub passes through and a discriminator 4 for double threads which likewise emits a signal to the cutting unit 5 when a double thread passes through.
  • a yarn cleaner additionally incorporates a store 6 according to the invention which is controlled by at least one of the two discriminators 3, 4 and acts upon the sensitivity of the discriminator 4 depending upon the storage condition.
  • the sensitivity level could, of course, also be varied elsewhere, for example, in an amplifier accommodated in the measuring head 2.
  • sensitivity must be controlled at least during the insertion or introduction phase of the yarn.
  • various modifications are possible both in the manner in which the store is controlled and in the manner in which the store is erased.
  • the signal generated by the discriminator 3 can be retained in the store 6, in which case the sensitivity of the discriminator 4 can be lowered for the double thread channel.
  • the signal generated by the discriminator 4 can be retained in the store 6 and the sensitivity of the discriminator 4 increased since its sensitivity is normally fairly low. If, however, a cut is initiated by a double thread, the sensitivity of discriminator 4 is increased. As already mentioned there are numerous alternatives for erasing the stored signal.
  • the store 6 can be controlled both by the discriminator 3 and by the discriminator 4, in which case the sensitivity of the discriminator 4 is reduced where the store 6 is controlled by the discriminator 3, and increased where it is controlled by the discriminator 4.
  • discriminator 3 for detecting slubs consists of a conventional Schmitt trigger which releases a signal at an output 22 when a predetermined input voltage is exceeded at an input 21.
  • one example of a discriminator 4 for double threads consists of an RC-section and a Schmitt trigger.
  • the RC-section has an input 31 which permits only signals for coarse or double threads to pass and the Schmitt trigger only releases a signal at an output 32 when a predetermined output voltage of the RC-section is exceeded.
  • a store circuit arrangement consists of a conventional bistable multivibrator wherein the inputs 41, 42 of the bistable multivibrator are connected to the outputs 22, 32 of the discriminators 3 and 4. If, therefore, a double thread, for example, passes through the measuring head, the discriminator 4 releases a signal at output 32 and hence at the input 41 of the bistable multivibrator making input transistor 43 conductive. The signal at one of the collectors of the bistable multivibrator can then be used for sensitivity control.
  • a circuit arrangement incorporates not only a discriminator 3, discriminator 4 and store 6, as above, but also uses certain elements in common.
  • a transistor 55 acts as an output transistor both for the discriminator 3 and the discriminator 4.
  • the inputs of the transistors 51 and 53 are still independent of one another so that the circuit is as it were formed by two Schmitt triggers with separate inputs but a common output.
  • the bistable multivibrator is also included in this circuit and consists of the transistors 52 and 54 and of the resistances 56, 57, 58 and 59. In this case, the multivibrator is directly controlled by the collector currents of the input transistors 5Land S3.
  • the circuit arrangement of FIG. 7 operates as follows. If, for example, a slub appears, a corresponding ON-signal is generated at the input 41 and the transistor 53 becomes conductive. As a result, the transistor 54 also becomes conductive, and remains conductive even after the signal at the input 41 has disappeared thereby blocking the transistor 53. If, on the other hand, a double thread appears, the transistor 51 becomes conductive, as does the transistor 52 which also remains conductive even after the signal at the input 31 has disappeared.
  • the response limit or sensitivity of the Schmitt trigger can be varied by means of the resistances 56 and 57. If, for example, the resistance 56 is greater than 57, the sensitivity of the Schmitt trigger is higher when the transistor 52 is conductive.
  • the required objective is achieved because there is an increase in sensitivity on the arrival of a double thread.
  • the sensitivity remains high until a sufiiciently large signal appears at the input 41, as a result of which the transistor 53 or 54 becomes conductive and the bistable multivibrator flips, i.e. the sensitivity is lowered again after the arrival of a slub.
  • circuits of this kind are attended by a disadvantage.
  • a yarn bobbin runs out of yarn, no cut can be made. Accordingly, the discriminator 4 is adjusted to a low sensitivity level.
  • the discriminator 4 is adjusted to a low sensitivity level.
  • a new yarn bobbin contains a double thread immediately at the beginning, the double thread is not detected on account of the inadequate sensitivity level.
  • This disadvantage can be obviated by controlling the store 6 only by the discriminator 3, i.e. by lowering the sensitivity of the' discriminator 4 after the discriminator 3 has been triggered by a slub.
  • a signal can now be received, as is known per se by the measuring head 2 incorporating an amplifier, indicating whether a yarn 1 is passing through. This signal erases the signal retained in the store.
  • the circuit arrangement shown in FIG. 7 is a very detailed example of a circuit.
  • the circuit has only to be amplified or supplemented in such a way that the signal indicating the passage of a thread which can be obtained in known manner from the A.C. voltage signal of the thread passing through, makes the transistor 54 conductive or blocks the transistor 52. This can be done by a positive impulse at the base of the transistor 54 or by a negative impulse at the base of the transistor 52, depending upon the polarity of the aforementioned signal.
  • the signal contained in the store 6 may even be erased by the impulse generated upon insertion of the yarn. It could also be erased after a certain time interval particularly in cases where, following a cut, the yarn travels normally again within a predetermined time, for example, in the case of automatic winding machines.
  • a yarn cleaner having a measuring head for passage of a yarn therethrough, a first discriminator for detecting the presence of a slub in the yarn in said head and emitting a signal in response thereto, a second discriminator havin an adjustable sensitivity for detecting the presence of a double thread in the yarn in said head and emitting a signal in response thereto, and a cutting device for receiving a signal from one of said discriminators to cut the thread; a store operatively connected to said first and second discriminators for receiving said signals therefrom, said store including a circuit arrangement responsive to a signal from at least one of said discriminators for storing the signal received and a control element for adjusting the sensitivity of said second discriminator in response to the signal stored in said circuit arrangement.
  • bistable multivibrator includes means for erasing the stored signal to flip said bistable multivibrator back to an initial position.
  • a method for reducing the number of needless cuts in an electronic yarn cleaner having an adjustable sensitivity to emit signals in response to the presence of slubs and double threads of predetermined size in a yarn passing therethrough comprising the steps of receiving a signal in response to the presence of a slub or double thread of predetermined size, storing said received signal, and
  • a method as set forth in claim 9 which further includes the step of erasing the stored signal to return the sensitivity of the yarn cleaner to the initial sensitivity.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Textile Engineering (AREA)
  • Quality & Reliability (AREA)
  • Filamentary Materials, Packages, And Safety Devices Therefor (AREA)
  • Spinning Or Twisting Of Yarns (AREA)
US599481A 1965-12-13 1966-12-06 Apparatus and method for reducing the number of unnecessary cuts of yarn Expired - Lifetime US3390441A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH1724965A CH437076A (de) 1965-12-13 1965-12-13 Verfahren und Vorrichtung zur Verminderung der Anzahl ungerechtfertigter Schnitte beim Einlegen von Garnen in elektronische Garnreiniger

Publications (1)

Publication Number Publication Date
US3390441A true US3390441A (en) 1968-07-02

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Application Number Title Priority Date Filing Date
US599481A Expired - Lifetime US3390441A (en) 1965-12-13 1966-12-06 Apparatus and method for reducing the number of unnecessary cuts of yarn

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US (1) US3390441A (xx)
AT (1) AT268940B (xx)
BE (1) BE690117A (xx)
CH (1) CH437076A (xx)
ES (1) ES334458A1 (xx)
FR (1) FR1504975A (xx)
GB (1) GB1171633A (xx)
NL (1) NL6613459A (xx)
SE (1) SE313931B (xx)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3758216A (en) * 1971-05-27 1973-09-11 Loepfe Ag Geb Electronic appliance for setting and checking electronic yarn clearers
US4566163A (en) * 1983-06-21 1986-01-28 Nippon Selen Co., Ltd. Automatic supervisory system for a warper

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3932667A1 (de) * 1989-09-29 1991-04-11 Rieter Ag Maschf Verfahren zur reinigung von garnfehlern sowie garnreiniger zur durchfuehrung des verfahrens

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3187568A (en) * 1960-03-15 1965-06-08 American Enka Corp Filament fault detector
US3258824A (en) * 1963-09-28 1966-07-05 Reiners Walter Apparatus for checking of travelling yarn in textile machinery
US3309754A (en) * 1960-09-23 1967-03-21 Metcalf Eric Self-regulating light-responsive devices
US3326481A (en) * 1964-08-31 1967-06-20 Deering Milliken Res Corp Stop motion apparatus

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3187568A (en) * 1960-03-15 1965-06-08 American Enka Corp Filament fault detector
US3309754A (en) * 1960-09-23 1967-03-21 Metcalf Eric Self-regulating light-responsive devices
US3258824A (en) * 1963-09-28 1966-07-05 Reiners Walter Apparatus for checking of travelling yarn in textile machinery
US3326481A (en) * 1964-08-31 1967-06-20 Deering Milliken Res Corp Stop motion apparatus

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3758216A (en) * 1971-05-27 1973-09-11 Loepfe Ag Geb Electronic appliance for setting and checking electronic yarn clearers
US4566163A (en) * 1983-06-21 1986-01-28 Nippon Selen Co., Ltd. Automatic supervisory system for a warper

Also Published As

Publication number Publication date
CH437076A (de) 1967-05-31
AT268940B (de) 1969-02-25
ES334458A1 (es) 1968-02-01
BE690117A (xx) 1967-05-02
SE313931B (xx) 1969-08-25
FR1504975A (fr) 1967-12-08
NL6613459A (xx) 1967-06-14
GB1171633A (en) 1969-11-26

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